In recent years, progress has been made in the research and development of organic EL devices, which are light-emitting elements that rely on the phenomenon of electroluminescence of organic material. The organic EL devices have a structure where an organic light-emitting layer is interposed between an anode and a cathode. The following describes a general structure of such an organic EL device. FIG. 8 is a partial cross-sectional view that schematically shows a structure of an organic EL device 10. As shown in FIG. 8, a gate electrode 12 is disposed on a substrate 11, and a gate insulating film 13 covers the gate electrode 12. A semiconductor layer 14 is disposed on a portion of the gate insulating film 13, which is located above the gate electrode 12. Also, a wiring layer for supplying power to an anode, which is described below, is formed on the gate insulating film 13. Specifically, SD electrodes 15 and 16 are formed on the gate insulating film 13, such that parts of the respective SD electrodes 15 and 16 are formed on the semiconductor layer 14 with a gap therebetween. Note that the SD electrodes 15 and 16 are made of molybdenum (Mo), for example. Hereinafter, a description is provided with the assumption that the SD electrodes 15 and 16 are made of Mo.
An interlayer insulating film 17 is formed to cover the SD electrodes 15 and 16. The interlayer insulating film 17 has, for example, a two-layer structure including a passivation film 18 and a planarizing film 19. The interlayer insulating film 17 has a contact hole 17ch formed therein, and an anode 21 is formed along the contact hole 17ch. In other words, a part of the anode 21 enters the contact hole 17ch so as to make contact with the SD electrode 16 in the contact hole 17ch. The anode 21 is made of aluminum (Al), for example. Hereinafter, a description is provided with the assumption that the anode 21 is made of Al.
A bank 22 is layered on a portion of the anode 21, which corresponds to an edge 21a of the anode 21 and the contact hole 17ch. An organic light-emitting layer 23 is layered on a portion of the anode 21, which is defined by the bank 22. A cathode 24 is formed on the organic light-emitting layer 23 and the bank 22, and a sealing film 25 is formed on the cathode 24.
Note that Patent literature 1 is known as prior art literature pertaining to a structure of an organic EL device.